My parents cat when I was a kid would always steal food from his plastic food bin, even with it in his dish. He liked the idea of thinking he was getting away with something. Since he always had unlimited access to dry food, it was never a big deal, just something to laugh at. They'd gotten the plastic bin after multiple bags getting torn open.

Sounds like his dirty looks are working on you...

You're lucky he doesn't meow you to death instead and/or touch your leg with the occasional claw to remind you that "hey! you forgot to put the food down"!

In other words, he's being a cat